Deploy: perfect_answer discussion_plan retry 1->2 (3 total attempts) to fix occasional empty-plan sessions

core/perfect_answer.py

@@ -159,12 +159,23 @@ def generate_session_artifacts(argument_text, *, reasoning="medium", verbosity="
 
     arts = _call()
     # The discussion plan is mandatory: the host-side state machine is
-    # disabled without it. If parsing yielded no plan, retry once.
-    if not (arts.get("discussion_plan") or "").strip():
-        print("[perfect_answer] discussion_plan empty; retrying once", flush=True)
+    # disabled without it. The model occasionally drops the DISCUSSION
+    # PLAN block (output budget exhaustion or model flakiness). Retry
+    # up to 2 more times — 3 total attempts. Real production case:
+    # session 20260601_195128_71512 had two consecutive empty attempts;
+    # a third would almost certainly have caught it.
+    MAX_RETRIES = 2
+    for attempt in range(1, MAX_RETRIES + 1):
+        if (arts.get("discussion_plan") or "").strip():
+            break
+        print(
+            f"[perfect_answer] discussion_plan empty; retry {attempt}/{MAX_RETRIES}",
+            flush=True,
+        )
         retry = _call()
         if (retry.get("discussion_plan") or "").strip():
             arts = retry
+            break
     return arts